Subsea functions, such as inspections and other functions, such are often required for structures disposed subsea such as on a blowout preventor (BOP) located subsea. Though often needed on demand, having a full-function remotely or autonomously operated vehicle available where and when needed is not always practical.
For example, remotely operated vehicles (ROV) are typically deployed subsea when and as needed but are often linked to a deploying ship by a tether management system, an assembly used to help deploy the ROV from the surface to the working depth. An ROV also typically requires an umbilical cable, usually an armored cable, that contains a group of electrical conductors and fiber optics to carry electrical power, video, and data signals between the operator and the tether management system. In the current art, a tether management system may be used in conjunction with an ROV for various purposes such as to pay a tether connected to the ROV in and out when the ROV reaches working depth. Typically, a tether management system is a garage-like device or cage which contains the ROV as the ROV is being lowered into the water or a separate top-hat like assembly which sits on top of the ROV as the ROV is being lowered into the water. Where used, the tether management system is used to relay the signals and power for the ROV down the tether cable. Once at the ROV, the electrical power is distributed between the components of the ROV.
A current art tether management system may comprise the ability to effect multiple functions such as lighting, an electronic control system, cameras, and an electro-hydraulic system to power various components during ROV deployment.